Process for making underground storage caverns

A process for making an underground cavern for injection and storage of natural gas in underground salt deposits which comprises:

• employing fresh water from ambient temperature reserves available at or near the salt deposit site,
• preheating the water to a temperature of between about 85-140 degrees F. by passing it through one side of a heat exchanger, with water on one side and warm brine on the other side, said warm brine having been produced by solution mining the salt deposit,
• employing an insulating layer of paint, plastic material or other suitable insulating material on the inner, outer or both surfaces of the injection tubing to limit the heat transfer rate between injection water and evolving brine and to increase cavern temperature,
• clarifying the solution mined warm brine which is at a temperature of between about 95-150 degrees F. to remove sand and other sediments before introduction into the heat exchanger,
• further heating the preheated fresh water exiting the water/brine heat exchanger to a temperature of between about 105-160 degrees F. by subjecting it to supplemental heating with an appropriate source of heat,
• injecting the resulting heated water into the salt deposit to cause a three fold accelerated dissolution of the salt thus more rapidly forming a cavern in substantially less time than would be required with unheated water,
• circulating the warm brine exiting the cavern either through a second cavern in series and then to one side of the heat exchanger or directly to the heat exchanger, thereby transferring its sensible heat to the fresh water,
• disposing or otherwise using the heat depleted brine in an environmentally acceptable manner, and
• evacuating the brine from the cavern for underground storage of natural gas.

A process for making an underground cavern for injection and storage of fluid or fluidized materials in bedded or domal salt deposits which comprises:

• employing fresh water from ambient temperature reserves available at or near the salt deposit site,
• preheating the water by passing it through one side of a heat exchanger, with water on one side and warm brine on the other side, said warm brine having been produced by solution mining the salt deposit,
• clarifying the solution mined warm brine to remove sand and other sediments before introduction into the heat exchanger,
• further heating the preheated fresh water exiting the heat exchanger by subjecting it to supplemental heating with an appropriate source of heat,
• injecting the resulting heated water into the salt deposit to cause accelerated dissolution of the salt thus more rapidly forming a cavern in substantially less time than would be required with unheated water,
• employing an insulating layer of paint, plastic material or other suitable insulating material on the inner, outer or both surfaces of the injection tubing to limit the heat transfer rate between injection water and evolving brine and to increase cavern temperature, and
• circulating the warm brine exiting the cavern either through a second cavern in series and then to one side of the heat exchanger or directly to the heat exchanger, thereby transferring its sensible heat to the fresh water.